未能识别有效的datetime格式
public static string gettijiaoconnect(string yewubianma, string yonghuxinming, string shouji, string telphoto, string anzhuangdizhi, string shenqingshijian, string anzhuangshijian, string shiyongqixian, string yewuleixing, string zhanghao, string diaodu, string anzhuangrenyuan, string paidanshijian, string wanchengshijian, string haoshi, string mac, string xiaxingdianpin, string mer, string shangxingdianpin, string buxian, string cm, string fenpei, string fenzhi, string zhongduan, string wuleixian, string yonghuxian, string ftou, string yingzhitou, string duijietou, string zujietou, string taidu, string jishu, string shiyongganshou, string dailishang, string beizhu, string qitacailiao)
{
//public static string gettreelist()
string strtijiao = "INSERT INTO 安装信息表(业务单编码, 用户姓名, 用户手机, 固定电话, 申请时间, 安装地址, 安装时间, 使用期限, 业务类型, 账号, 调度, 安装人员, 派单时间, 完成时间, 耗时, MAC地址, MER, 下行电平, 上行电平, 布线, CM, 分配器, 分支器, 终端盒, 五类线, 用户线, F头, 英制头, 对接头, 竹接头, 态度, 技术, 使用感受, 代理商, 备注, 其他材料) values( ' " + yewubianma.Trim() + " ', ' " + yonghuxinming.Trim() + " ', ' " + shouji.Trim() + " ', ' " + telphoto.Trim() + " ', ' " + anzhuangdizhi.Trim() + " ', " +Convert.ToDateTime(shenqingshijian) + ", "+Convert.ToDateTime(anzhuangshijian)+ ", ' " + shiyongqixian.Trim() + " ', ' " + yewuleixing.Trim() + " ', ' " + zhanghao.Trim() + " ', ' " + diaodu.Trim() + " ', ' " + anzhuangrenyuan.Trim() + " ', " + Convert.ToDateTime(paidanshijian) + ", "+ Convert.ToDateTime(wanchengshijian)+ ", ' " + haoshi.Trim() + " ', ' " + mac.Trim() + " ', ' " + xiaxingdianpin.Trim() + " ', ' " + mer.Trim() + " ', ' " + shangxingdianpin.Trim() + " ', ' " + buxian.Trim() + " ', ' " + cm.Trim() + " ', ' " + fenpei.Trim() + " ', ' " + fenzhi.Trim() + " ', ' " + zhongduan.Trim() + " ', ' " + wuleixian.Trim() + " ', ' "